Genesis 22:15-18

And the angel of Jehovah called unto Abraham a second time out of heaven, and said, By myself have I sworn, saith Jehovah, because thou hast done this thing, and hast not withheld thy son, thine only son, that in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heavens, and as the sand which is upon the sea-shore; and thy seed shall possess the gate of his enemies; and in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.